I have laid out my arguments, supported by the manga unlike yours and you have chosen to ignore them.
Luffy confidently told his shadow to come back, and Moriah started spitting up shadows, Luffy had won at that point, it was a chain reaction.
Luffy knows the strength and state of his enemies after finisher attacks, as shown many many times in the manga.
Luffy knew the scenario after the Lucci fight required him to move and run away, he couldn't give into the fatigue as he could in TB. This really isn't that complicated, I don't know how you can end up with such a bad take.